Well treatments such as fracturing are frequently performed using a series of plugs that have a passage through them that is surrounded by a ball seat. A repeating pattern of setting a plug and releasing from the plug with a perforating gun to fire the gun and then to either remove the gun and drop a ball or to drop a ball while the gun is still in the hole with the final step using pressure against the seated ball in the plug for the treatment of a part of the adjacent formation. Typically a bottom up direction is employed of this pattern as further portions of the surrounding formation are treated. When the entire formation is treated the plugs need to be removed before production or injection begins. This can be done by milling out all the plug which can be time consuming. Parts of the plugs can be made of disintegrating materials but the remaining components still need either to be drilled out, pushed to bottom or circulated out. The plugs themselves are costly to produce and present some inherent risks that they will not properly set. Some jobs require a large number of plugs regardless of whether they are all set initially and then sequentially sealed off with progressively larger balls or are run in and set sequentially.
Also relevant in general to the subject of barriers that disappear or degrade are U.S. Pat. Nos. 8,794,335; 8,668,119; 8,342,240; 8,297,364; 7,661,481; 7,762,342; 7,461,699; 7,451,815; 5,103,911; 3,216,497; 2,261,292; 2,214,226; 20130299185 and 2014/0027127. Of particular significance is 20140014339 FIG. 11 which shows a tool that sets a disintegrating member that comes equipped with a ball seat.
The present invention is a departure from these known techniques in that instead of the plugs it encompasses delivery of a clad with a variable diameter swage to allow in essence the creation of a passage with a surrounding seat to accept an object against which pressure can be held to perform the treating operation. The clad is made of a disintegrating material such as a controlled electrolytic material so that after a time or with exposure to heat or well fluids to name some examples, the clad simply disintegrates. One trip operation can be accomplished with the running in of a bottom hole assembly that has the variable swage and the actuation device to move and build the swage after some expansion but to also support a gun and a ball dropping device so that the multi-diameter expansion can take place and the bottom hole assembly raised further after the swage clears the clad so that the gun can be operated to create perforations. The bottom hole assembly can then be retrieved and the ball dropped to close off the clad so that a treatment operation can then immediately begin into the perforations. This can be repeated as many times as needed to cover the entire interval of the formation. Over time the clads and balls released onto the clads simply disintegrate. Those skilled in the art will appreciate other aspects of the present invention from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing the full scope of the invention is to be determined from the claims.